We have this plant that has grown up in our barn and it has very little light and no water but it is doing well. We would like to know if you know what it is and we think it's about to flower soon. It's about knee high, and it came up through a pallet with plastic with scattered hay on top. we use to store hay there about 6 years ago when we had horses. This plant has never came up before till this year. Hope you can help us to identify what it is.